The present invention relates to an arrangement for mounting, on a support frame, the top end of a heat exchange module of a heat recovery steam generator and a method for mounting a heat exchange module in the supporting framework of a heat recovery steam generator.
According to U.S. Pat. No. 5,339,891, heat recovery steam generators have typically consisted of a vertically oriented heat exchanger comprising spirally-finned tubes located inside an externally supported box type structure. Further, according to the '891 patent, known modular arrangements typically comprise a finned tube heating surface that is bundled complete with top and bottom headers. The finned tube heating surface is shipped in a horizontal position and rotated at the erection site to a vertical orientation.
The modular finned tube heating surface acts as a heat exchanger to effect the exchange of heat from one fluid such as, for example, exhaust gas from a gas turbine, to another fluid such as water circulating in the tubes forming the finned tube heating surface. These heat exchanger modules are typically supported in a structural steel framework and one common approach to erecting these heat exchanger modules involves raising each modular heat exchanger above a bay formed within the structural steel framework and thereafter lowering the heat exchanger module into the bay. However, a drawback to this erection method is the need for a crane having sufficient height to lift the modular heat exchanger so that the bottom end of the modular heat exchanger clears the top of the bay. A crane with this capability may be unavailable or costly. Accordingly, the need exists for a mounting arrangement for a modular heat exchanger of a heat recovery steam generator which facilitates the installation of the heat exchanger module in the structural steel framework which supports it.